It is known to provide an air seeder which may be towed by a vehicle such as, for example, a tractor. Typical air seeders deliver seed and fertilizer to outlets at an elevated air pressure provided by a fan. However, with the desire to plant seeds as quickly as possible, it has become apparent that with excessive elevated air pressures seeds may bounce against a ground surface so that the seeds do not rest in their intended position within a trench, and therefore may not germinate. In turn, the lack of germination of these displaced seeds results in lower yield and, in turn, lower profits.
In order to avoid seed bounce, it has been proposed to provide diffusers such as the kind marketed under the trade mark “D-Cup Diffuser”. However, in using diffusers of this kind, individual diffusers are fitted to each seeding line or opener of the air seeder and, because there may be over 50 seeding lines on a single air seeder, the purchase of the required number of diffusers is typically very expensive. Moreover, with so many separate diffusers, significant maintenance is required in checking and maintaining proper operation of the diffusers.
Examples disclosed herein seek to provide an improved air seeder venting system.